[PATCH 6.6 129/166] md/raid1,raid10: dont ignore IO flags

Greg Kroah-Hartman
2026-04-24T13:38:59Z

From: Yu Kuai <yukuai3@huawei.com>

commit e879a0d9cb086c8e52ce6c04e5bfa63825a6213c upstream.

If blk-wbt is enabled by default, it's found that raid write performance
is quite bad because all IO are throttled by wbt of underlying disks,
due to flag REQ_IDLE is ignored. And turns out this behaviour exist since
blk-wbt is introduced.

Other than REQ_IDLE, other flags should not be ignored as well, for
example REQ_META can be set for filesystems, clearing it can cause priority
reverse problems; And REQ_NOWAIT should not be cleared as well, because
io will wait instead of failing directly in underlying disks.

Fix those problems by keep IO flags from master bio.

Fises: f51d46d0e7cb ("md: add support for REQ_NOWAIT")
Fixes: e34cbd307477 ("blk-wbt: add general throttling mechanism")
Fixes: 5404bc7a87b9 ("[PATCH] Allow file systems to differentiate between data and meta reads")
Link: https://lore.kernel.org/linux-raid/20250227121657.832356-1-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
[ Harshit: Resolve conflicts due to missing commit: f2a38abf5f1c
("md/raid1: Atomic write support") and commit: a1d9b4fd42d9
("md/raid10: Atomic write support") in 6.12.y, we don't have Atomic
writes feature in 6.12.y ]
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Based on Harshit's backport for 6.12, fixed minor conflicts for 6.6. ]
Signed-off-by: Charles Xu <charles_xu@189.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/raid1.c | 4 ----
drivers/md/raid10.c | 7 -------
2 files changed, 11 deletions(-)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 4c1f86ca55208..d313e9834d447 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1214,8 +1214,6 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
struct raid1_info *mirror;
struct bio *read_bio;
struct bitmap *bitmap = mddev->bitmap;
- const enum req_op op = bio_op(bio);
- const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
int max_sectors;
int rdisk;
bool r1bio_existed = !!r1_bio;
@@ -1315,7 +1313,6 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
read_bio->bi_iter.bi_sector = r1_bio->sector +
mirror->rdev->data_offset;
read_bio->bi_end_io = raid1_end_read_request;
- read_bio->bi_opf = op | do_sync;
if (test_bit(FailFast, &mirror->rdev->flags) &&
test_bit(R1BIO_FailFast, &r1_bio->state))
read_bio->bi_opf |= MD_FAILFAST;
@@ -1537,7 +1534,6 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,

mbio->bi_iter.bi_sector = (r1_bio->sector + rdev->data_offset);
mbio->bi_end_io = raid1_end_write_request;
- mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
if (test_bit(FailFast, &rdev->flags) &&
!test_bit(WriteMostly, &rdev->flags) &&
conf->raid_disks - mddev->degraded > 1)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 8546ef98bfa7e..6bcf6852c2000 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1168,8 +1168,6 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
{
struct r10conf *conf = mddev->private;
struct bio *read_bio;
- const enum req_op op = bio_op(bio);
- const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
int max_sectors;
struct md_rdev *rdev;
char b[BDEVNAME_SIZE];
@@ -1250,7 +1248,6 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
read_bio->bi_iter.bi_sector = r10_bio->devs[slot].addr +
choose_data_offset(r10_bio, rdev);
read_bio->bi_end_io = raid10_end_read_request;
- read_bio->bi_opf = op | do_sync;
if (test_bit(FailFast, &rdev->flags) &&
test_bit(R10BIO_FailFast, &r10_bio->state))
read_bio->bi_opf |= MD_FAILFAST;
@@ -1267,9 +1264,6 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
struct bio *bio, bool replacement,
int n_copy)
{
- const enum req_op op = bio_op(bio);
- const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
- const blk_opf_t do_fua = bio->bi_opf & REQ_FUA;
unsigned long flags;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev;
@@ -1295,7 +1289,6 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
mbio->bi_iter.bi_sector = (r10_bio->devs[n_copy].addr +
choose_data_offset(r10_bio, rdev));
mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_opf = op | do_sync | do_fua;
if (!replacement && test_bit(FailFast,
&conf->mirrors[devnum].rdev->flags)
&& enough(conf, devnum))
--
2.53.0